Thermal treatments on polyimide: kapton

1
Thermal treatments on polyimide kapton H
CNISM

• Matteo Belli - CNISM

2
Outline

• Introduction
• Thermal treatments on bulk polyimide (kapton H)
• Preliminary optical measurements on
  proton-irradiated kapton (from HE-3)
• Conclusions

3
Why kapton ?

• Principle carbon, disorder, and light atoms to
  magnetism
• starting from a polymer, not a crystal

4
Why kapton ?

• Thermal treatments at 520C are reported to yield
  magnetic kapton

Treatment at 520 Con a 25 µm film
(J T-1 kg-1 emu g-1)
Kaburagi et al., J. Mater. Res. 17(8), (2002)
2000-2006
5
XRD

• Correlation with structure modifications
• (amorphous structure)

Kaburagi et al., J. Mater. Res. 17(8), (2002)
2000-2006
6
Why kapton ?

• Proton-irradiated kapton gives rise to magnetic
  spots, like irradiated graphite(HE-3 P.
  Esquinazi, FERROCARBON kick-off meeting)

7
Thermal treatments

• Many parameters
• Width of the film
• Maximum temperature (outgas, disorder,
  decomposition, )
• Thermal ramp for heating and cooling
• Duration of the treatment
• Fixed width (125 µm)

8
Thermal treatments

• Thermal treatment with 2-step ramp (up to 520C,
  600C or 700C)

9
SQUID
10
SQUID
Mg, not cg !!!
11
XRD
12
Thermal treatments

• Thermal treatment with single ramp and plateau at
  maximum temperature (up to 520C or 750C)

13
XRD
14
SQUID
15
Thermal treatments

• Different annealing time at 750C (1h or 2h)

16
SQUID

• Kapton treated 2h at 750C 3.6 ?10-3 emu/g
  saturation without hysteresis

17
X-rays Irradiation

• X-rays tube
• Target W
• 1.0 mm Be window
• 30 min irradiation (40 kV, 40 mA)
• NO dark spots.

18
H irradiated kapton
Irradiated spots, spaced by 910 µm
19
FT-IR spectroscopy

• Transmission configuration
• Comparison non-irradiated vs. irradiated region
  (300 spots)
• No significant changes

20
Raman spectroscopy

• l 647 nm, 10 mW power
• Irradiated kapton shows
• smaller and broader lines
• more luminescence
• as compared to the non-irradiated region

21
Raman spectroscopy

• Low-frequency region allows investigation of
  vibrational modes in antiferromagnets
• No significant changes

22
IR and Raman

• Optical measurements lead to the conclusion that
• Kapton does not decompose significantly
• Irradiated regions develop an increase in the
  disorder
• Detailed Raman measurements will give more
  information on
• Disorder (also vs. depth)
• Radiation damage

23
Conclusions

• Bulk kapton is increasingly interesting, though
  a systematic study is still in progress
• Optical measurements on proton-irradiated kapton
  will be a powerful tool to correlate magnetism
  and structure in the polymer

24
(No Transcript)
25
Kapton H pyrolysis
Pyrolysis range 500-1200C